1. Field of the Invention
The present invention relates to a projection display provided with an optical unit to optically process the luminous flux emitted from a light source lamp unit and project the magnified image on a projection surface by a projection lens unit, a power source unit to feed the power to the optical unit, and an external case to store the optical unit and the power source unit.
2. Description of Related Art
A projection display provided with an optical unit to optically process the luminous flux emitted from a light source lamp unit and project the magnified image on a projection surface by a projection lens unit, a power source unit to feed the power to the optical unit, an external case to store the optical unit and the power source unit, and a plurality of circuit substrates to control the optical unit has been conventionally known.
The optical unit of the projection display is provided with a color separation optical system to separate the luminous flux emitted from a light source lamp into the luminous flux of the primary colors, a modulation system to emit each of the separated luminous flux as the modulated luminous flux based on the image information, and a color synthesis optical system to synthesize each modulated luminous flux and emit it to the projection lens unit, in addition to the light source lamp unit and the projection lens unit which are mentioned above.
The color separation optical system and the modulation system of the optical unit are stored and arranged together with the light source lamp unit in a light guide in which the prescribed optical path is secured. The light guide is split into an upper part and a lower part to hold the optical elements such as the color separation optical system from the upper part and the lower part.
The color synthesis optical system and the projection lens unit of the optical unit are mounted on a head plate provided with a vertical wall and a bottom wall extending in the horizontal direction from a lower end of the vertical wall. More specifically, a base end side of the projection lens unit is fixed to the vertical wall, the color synthesis optical system is arranged on the bottom wall, and the projection lens unit and the color synthesis optical system are integrated in a condition where the optical axes are aligned with each other through the vertical wall.
The head plate is fixed to the light guide by screwing the lower end part of the vertical wall to a lower light guide so that the modulated luminous flux is incident on the color synthesis optical system on the head plate from the modulation system in the light guide. In this projection display, it is strongly desired to integrate the system to facilitate the handling, and miniaturized to a minimum.
These projection displays have the following disadvantages.
(1) A cooling mechanism to cool a light source lamp, a power source unit and a circuit substrate which are stored in the external case is built in the above-mentioned projection display. The power source unit is cooled because the power source unit is provided with a primary side active filter, a power source, a ballast, etc., and the elements to be mounted thereon are the source of heat generation, a heat sink is fixed to each element to store the heat, and the heat sink is cooled.
However, the above-mentioned various kinds of optical systems must be mounted on the projection display to obtain the parallel luminous flux, and the ratio in volume of the optical system in the external case is increased. If the display is fully cooled, each component of the display can not be arranged too closely, raising a problem of limitation in miniaturization. Even if each component is arranged in a close contacting manner, there raises a problem that no efficient cooling can be performed.
(2) In the above-mentioned projection display, the head plate is connected to the light guide at the lower end part of the vertical wall, the distance between the connection part and the center of gravity of the projection lens unit is long, and the vertical wall can be deflected by the load of the projection lens unit to cause the deviation of the optical axis of the color synthesis optical system from the optical axis of the projection lens unit. Because the moment caused by the disturbance and impact at a part to which the projection lens unit is fixed generates the bending stress in a root part of the bottom wall and vertical wall of the head plate, the bending stress also has to deal with this problem. Thus, the vertical wall must be reinforced by providing a large number of ribs, raising a problem that the structure of the head plate is complicated.
The first object of the present invention is to provide a projection display capable of miniaturizing the display, and efficiently cooling the inside of the display in the projection display provided with an optical unit to optically process the luminous flux emitted from a light source lamp unit and project the magnified image on the projection surface by a projection lens unit, a power source unit to feed the power to the optical unit, and an external case to store said optical unit and said power source unit.
The second object of the present invention is to provide a projection display capable of simplifying the structure of a head plate in the above-mentioned projection display.
The first aspect of the present invention provides a projection display provided with an optical unit to optically process the luminous flux emitted from a light source lamp unit and project the magnified image on the projection surface by a projection lens unit, a power source unit to feed the power to the optical unit and a light source lamp unit, and an external case to store said optical unit and said power source unit, wherein in that an air inlet to suck the air for cooling from the outside of the display, and a discharge port to discharge the air inside the display outside are formed in said external case, one end part of said power source unit is arranged in the vicinity of said air inlet, an opening for suction to suck the air for cooling into said power source unit is provided in said one end part, an opening for discharge to discharge the air inside said power source unit is provided on the other end part of said power source unit, said light source lamp unit is arranged between the discharge port formed in said external case and an opening for discharge provided on the other end part of said power source unit, and the air to be discharged from the opening for discharge formed in the said other end part is distributed inside said light source lamp unit and utilized for the air for cooling said light source lamp.
In the first aspect of the invention, the power source unit is provided with the suction opening and the discharge opening, and the inside of the power source unit can be efficiently cooled independently from other parts, and the optical unit and the power source unit are closely arranged to miniaturize the display.
The above-mentioned opening for suction is preferably provided with a suction fan.
Because the air for cooling can be forcibly sucked inside the power source unit by the suction fan, the cooling efficiency inside the power source unit can be further improved.
The above-mentioned discharge port is preferably provided with a shielding means to cover the discharge port from the inside, and, for example, a shielding means of louver type which is formed by laminating a plurality of plate-shaped material having the length astride the discharge port is preferably adopted.
Because the shielding means is provided on the discharge port, no light is leaked from said discharge port even when the light source lamp unit is arranged in the vicinity of the discharge port, and convenience of the projection display is further improved.
Because the shielding means is formed of louver shape, the discharge from the discharge port is not shielded by the shielding means, and an appropriate discharge condition can be ensured.
Furthermore, the above-mentioned light source lamp unit is preferably provided with a light source lamp comprising a lamp body and a reflector, a box-shaped lamp housing to store the light source lamp, and a vent hole to lead said air for cooling to said lamp body is preferably formed on a side of said lamp housing which is approximately orthogonal to an opening surface of the reflector.
Because the lamp housing to constitute the light source lamp unit is provided with the vent hole, the air for cooling is fed to the lamp body through this vent hole to promote the cooling efficiency of the light source lamp unit.
The above-mentioned vent hole is preferably provided with a deflector distributing plate to lead the air for cooling to the lamp body.
Because the vent hole is provided with the deflector distributing plate, the lamp body can be appropriately cooled when the air for cooling is distributed through the vent hole, and the cooling efficiency of the light source lamp unit is further promoted.
When the optical unit has a color separation optical system to separate the luminous flux into a plurality of luminous fluxes, a modulation system to modulate each of the separated luminous fluxes based on the image information and emit it as the modulated luminous flux, and a color synthesis optical system to synthesize each modulated luminous flux and emit it into the projection lens unit, the above-mentioned air inlet is preferably formed below said color synthesis optical system.
Because the air inlet is formed below the color synthesis optical system, the air for cooling to be sucked from the outside first cools the color synthesis optical system and the modulation system.
After cooling the color synthesis optical system and modulation system, the air for cooling can cool other hotter parts such as the light source lamp unit, the power source unit and circuit substrate, and the inside of the display can be efficiently cooled without waste.
Furthermore, when a circuit substrate to control said optical unit is provided on an upper part of the optical unit, a part of the air for cooling to be sucked from the air inlet is preferably collected to an upper part of said color synthesis optical system, distributed along the circuit substrate, and discharged from said discharge port.
Not only one circuit substrate but also a plurality of circuit substrates having different functions may be laminated on an upper part of the optical unit, and, for example, a driver substrate and a video substrate may be provided on the optical unit in a laminated condition.
Because the air for cooling is distributed along the circuit substrate hotter than the color synthesis optical system and modulation system, the air cooling the color synthesis optical system and modulation system can be used as the air for cooling for the circuit substrate, and further, the air after cooling can be used as the air for cooling the hotter light source lamp unit, and the cooling efficiency in the display is further improved.
When the above-mentioned air inlet is formed below the color synthesis optical system, a dust-proof means is preferably provided above the color synthesis optical system.
Because the dust-proof means is provided above the color synthesis optical system, reverse flow of dust, etc. to the color synthesis optical system side can be prevented when the flow of the air for cooling is stopped.
The second aspect of the present invention provides a projection display provided with an optical unit to optically process the luminous flux emitted from a light source lamp unit and project the magnified image on the projection surface by a projection lens unit, a power source unit of approximate L-shape to feed the power to said optical unit and light source lamp unit, and an external case to store said optical unit and said power source unit, characterized in that an air inlet to suck the air for cooling from the outside of the display is formed on said external case, said power source unit is arranged aside said optical unit, and one end part is arranged in the vicinity of said projection lens unit.
In the second aspect, because an opening for suction of the power source unit is formed in the vicinity of the projection lens unit, the air for cooling can be introduced from the gap between the external case and the projection lens unit, and the power source unit can be efficiently cooled similar to the above-mentioned structure, and the display can be miniaturized. In particular, the power source unit is of approximate L-shape, the power source unit can be efficiently stored in a space demarcated by the external case, the optical unit and the projection lens unit, and the display can be further miniaturized.
An opening for suction to suck said air for cooling into the power source unit is provided in one end part of the above-mentioned power source unit, an opening for discharge to discharge the air in said power source unit is provided on the other end part of the power source unit, and said one end part of the power source unit is preferably arranged in the vicinity of the air inlet provided in the external case.
Because the power source unit is of approximate L-shape, the opening for suction can be arranged in the vicinity of the air inlet to further improve the cooling efficiency of the power source unit.
The above-mentioned light source lamp unit is preferably arranged between the port for discharge formed in said external case and an opening for discharge provided on the other end part of the power source unit.
Because the light source lamp unit is arranged between the port for discharge and the opening for discharge, the air for cooling which cools the inside of the power source unit can be used for cooling the hotter light source lamp unit to further improve the cooling efficiency in the display.
The third aspect of the present invention provides a projection display provided with an optical unit to optically process the luminous flux emitted from a light source lamp unit and project the magnified image on the projection surface by a projection lens unit, wherein an outside temperature detecting means to detect the temperature outside the display and an inside temperature detecting means to detect the temperature inside the display are provided, and the cooling control of said projection display is performed according to the differential temperature between the inside temperature to be detected by said inside temperature detecting means and the outside temperature to be detected by said outside temperature detecting means.
The cooling control of the display is defined as the control of the air volume by a suction fan, a discharge fan, etc. provided, for example, in the display, or the control to turn off the lamp body of the light source lamp unit with large heat generation.
In the third aspect of the invention, the cooling control of the display is performed according to the differential temperature between the outside temperature and the inside temperature, and it is possible to determine the actual temperature of the components of the display by the temperature of the air for cooling to be discharged, and appropriate cooling control can be performed.
The above-mentioned projection display is provided with the external case to store the light source lamp unit and the optical unit, an air inlet to suck the air for cooling from the outside of the display is formed in the external case, and the outside temperature to be detected by the outside temperature detecting means is preferably the temperature of the air to be sucked from the air inlet provided in the external case.
Because the temperature to be detected by the outside temperature detecting means is the temperature of the air to be sucked from the air inlet, the outside temperature of each component of the projection display immediately before cooling can be detected, and the cooling control of better accuracy can be performed.
The fourth aspect of the present invention provides a projection display provided with a optical unit to optically process the luminous flux emitted from a light source lamp unit and project the magnified image on the projection surface by a projection lens unit, a power source unit to feed the power to the optical unit, and an external case to store said light source lamp unit, said optical unit, and said power source unit, wherein said optical unit is provided with a color separation optical system to separate said luminous flux into a plurality of color luminous fluxes, a modulation system to modulate each of said separated luminous fluxes based on said image information and emit it as the modulated luminous flux, and a color synthesis optical system to synthesize each of said modulated luminous flux and emit it to said projection lens unit, said projection lens unit and said color synthesis optical system are mounted on a head plate, a supporting part to support said head plate is provided in said external case, and said head plate is provided with a vertical wall to which a base end side of said projection lens unit is fixed, a bottom wall which is extended in the horizontal direction from a lower end part of the vertical wall to support said color synthesis optical system, and a supported part to be supported by said supporting part provided in said external case.
Said supported part is preferably provided on said vertical wall in the range of height from the position of an upper end to the position of a lower end of a contour of said projection lens unit.
The range of height from the height position of an upper end to the height position of a lower end of a contour of said projection lens unit includes the same height position as the respective height position of the upper end and the lower end of the projection lens unit.
In the fourth aspect of the invention, the supported part is provided at the height position in the range of the contour height of the projection lens unit in the vertical wall. So the bending stress generated in a root part (a lower end part) of the vertical wall of the head plate by the bending moment generated according to the center of gravity of the projection lens unit can be efficiently diffused and absorbed by the supporting part of the external case, the bending stress can be mitigated, and deflection of the vertical wall can surely be prevented. Thus, no complicated reinforcement structure is required to be installed on the vertical wall, and the structure of the head plate can be simplified. Furthermore, the projection lens unit and the color synthesis optical system can be correctly positioned through the vertical wall, and the deviation of the optical axis can surely be prevented.
When the contour of the projection lens unit is approximately as large as that of the vertical wall, the supported part is preferably provided at the height position of not less than xc2xc from the lower end of said vertical wall when the whole height of the vertical wall is defined as 1, and more preferably, in the height range between ⅓ and ⅔.
Further, said supported part is preferably provided approximately as high as the optical axis of said projection lens unit.
If the supported part is provided at such a position, the center of gravity of the projection lens unit can be approximately as high as the supported part, or the supported part can be higher than the center of gravity, the load on the projection lens unit can be efficiently diffused, and the structure of the vertical wall can be further simplified.
The supported part comprises a fixed surface which is projected from said vertical wall parallel to said bottom wall and supported and fixed by said supporting part, and reinforcement ribs orthogonal to the fixed surface are preferably erected on said vertical wall.
When the supported part comprises the fixed surface projected on the vertical wall, the supported part can also be used as reinforcement ribs to reinforce the vertical wall. The rigidity of the vertical wall can further be improved using a simple structure by provided reinforcement ribs orthogonal to the fixed surface.
Furthermore, said head plate is preferably made of magnesium formed body, and the weight of the display can be reduced and the excellent formability can be secured thereby because the specific gravity can be reduced. Moreover, magnesium can improve the reliability of the impact resistance while the weight is reduced by taking advantage of the thin-walled construction to a maximum.